Fluid pump



`Dec. 8, M36., w. H. HERMSDORF ET AL 2?@.637503 FLUID yPUMP Filed Dec.8, 1955 i 3 Sheets-Sheet l l De@ 8, 19361 w. H. HERMSDORF ET AL2,063,503

FLUID PUMP Filed Dec. 8, 1933 3 Sheets-Sheet 2 Dec. 193%.. W. H.HERMSDORF ET A1. l EE FLUID PUMP Filed Dec. 8, 1933 3 Sheets-Sheet I5 J51 f L Fi* i gli f Il 57" Mzvlelf.

` Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE FLUID PUMPApplication December 8, 1933, Serial No. 701,442

1 Claim.

This invention relates to improvements in uid pumps and refersparticularly to a fluid pumpl of the rotary type having a plurality ofpistons so eccentrically disposed upon the pump shaft as to dynamicallybalance the shaft and permit of the employment of relatively high pumpspeeds.

The object and advantages of our invention will be apparent from theaccompanying drawings and detail description.

In the drawings, Fig. 1 is a transverse sectional View taken on lineI--I of Fig. 3 illustrating an embodiment of our invention.

Fig. 2 is a sectional view taken on line 2--2 of Fig. 1.

lo Fig. 3 is a sectional view taken on line 3-3 of Fig. 1.

Fig; 4 is a sectional View taken on line 4-4 of Fig. 1.

Fig. 5 is a fragmentary sectional view illustrating particularly theinlet and discharge ports of one of the cylinders,

Fig. 6 is a fragmentary sectional view, illustrating a slightly modiedport construction.

Fig. '7 is a top plan View of. the portion of the device shown in Fig.6.

Fig. 8 is a fragmentary detail elevation, parts being broken away andparts being shown in section, of another modified form of portconstruction.

I Fig. 9 is a top plan View of the portion of the device shown in Fig.8.

, Referring in detail to the drawings, I and 2 indicate drums orcylinder walls closed-atl oppositeV ends by heads 3 and 4 and separatedby an internal partition 5. Drums I and 2, heads 3 and 4 and partition5, is assembled as a unitary structure, being secured together by bolts6 which pass through members I, 2, 3, 4 and 5. The body thus formed isdivided into two compartments or cylinders l and 8.

Bosses 9 and I0 may be formed on heads 3 and 4 respectively, said bossesbeing hollow and adapted to carry bearings II and I2 respectively. Ashaft I3 may be journalled in bearings II and I2, and may pass throughcylinders 'I and 8, said shaft being coaxially disposed` with respect tothe Walls I and 2. The opening in boss I0 may be closed at the end byplug I4 and a packing gland and nut I5 adapted to confine packingmaterial I6, may serve to prevent leakage of fluid or oil along shaft I3at its opposite end.

Eccentrics I1 and I8 may be positioned upon shaft -I3 within cylinder 'Iand 8 respectively, said eccentrics being locked upon the shaft by meansof keys I9 which may be maintained in place by (Cl. 10S- 132) set screws20, one only of -which is shown in the drawings. In the embodimentshown, the eccentrics Il and I8 are displaced 180 apart, one pistonbeing adapted to counterbalance the other when shaft I3 is rotated, aswill be hereinafter 5 more fully described. However, if desired, two ormore cylinders and eccentrics may be used so long as the angulardisplacement of the eccentrics is uniform. For instance, if three areused, the displacement may be 120; if four are 10 used, the displacementwill be and so on in equal multiples of 360.

Eccentrics I'I and I8 may be circular in section and may be adapted tocarry pistons 2| and 22 respectively, said pistons being adapted to ride15 upon the circular periphery of the eccentrics. the throw of theeccentrics, that is, the distance between the center line of shaft I3and the axes of eccentrics I'I and I8 is such, taken in conjunction withthe radii of pistons 2| and 22 20 which are circular in section, as topermit the periphery of the pistons, when shaft I3 is rotated, toosculate or be brought into a tangential relationship with the innerwalls of the cylinders.

Above each of the cylinders 'I and 8, drums I 25 and 2 may be providedwith transverse bores 23 and 24, said bores being in communication witheach other and with the upper portion of the cylinders. A vane 25 may bepositioned at one end in a slot provided in the upper portion of 30 eachof the pistons 2| and 22, said vanes being rigidly secured within saidslots by means of pins 25. The opposite portions of vanes 25 may extendupwardly into bores 23 and 24. Halfround members 2l may be positionedwithin 35 each bore 24, each vane 25 extending between said members. Theconstruction is such that when shaft I3 is rotated, pistons 2| and 22are prevented from rotating by means ofvanes 25. However, by theprovision of the half-round 40 members 2l which form a knuckle joint andby means of the slidable relationship between vane 25 and half-roundmembers 21, pistons 2| and 22 are permitted to move in an orbitalfashion Within said cylinders, a portion of each of the 45 pistons beingin sliding contact with the walls of the respective cylinder.

The upper portions of drums I and 2 may be provided with bores 28 and 29respectively, said bores communicating at one end with cylinders 1 50and 8 respectively, the opposite ends of said bores opening intocompartment 30 formed by the hollow Cap 3| which may be mounted on theupper portion of said drums by means of machine screws 32 or the like.Cap 3| may be provided 55 with a boss 33 in which an aperture 34 isformed and through which fluid may be drawn into the cylinders.

The upper portion of drum 2 may be provided with a bore 35 which mayextend transversely through the thickness of said drum. Head 4 may beprovided with an opening 36 as may also partition 5, openings 36 in saidhead and partition forming a continuation of bore 35. Drum I may beprovided with recess 3l which may be in communication with opening 35 inpartition 5. Conduits 38 and 39 may be respectively provided in drumsand 2, said conduits respectively connecting into recess 3l and bore 35,permitting communication between cylinders 'I and 8 and outlet pipe 49which may connect into opening 36 provided in head 4.

It is to be observed that bores 28 and 29 which serve as the intake forcylinders 'I and 8, and conduits 38 and 39 which serve as dischargeports or exhausts for said cylinders, are positioned on opposite sidesof vanes 25. The construction of vanes 25 and knuckle joints 2l is suchas to prevent direct communication between the inlet and outlet of thecylinders. Consequently, it can readily be seen that communicationbetween the inlet and outlet of each cylinder must take place throughthe medium of the orbital travel of each piston.

In operation, shaft 3 may be driven by any suitable prime mover, notshown. Assume for the sake of illustration that shaft I3 is driven in acounterclockwise direction as viewed in Fig. 1. As has been hereinbeforedescribed, eccentrics I'I and I8 are displaced 180 away from each other.Consequently, in the phase of operation shown in Fig. 1, piston 2| is atthe upper portion of its orbital path whereas piston 22 is at thediametrically opposite position. In the period of. operationillustrated, piston 22 is moving in a counterclockwise orbital path andis forcing air through outlet 39. Simultaneously air is being drawn bysaid piston through inlet 29. Piston 2| has just completed its cycle andis about to open discharge port 38 and close inlet 28. As said pistoncontinues its counterclockwise orbital movement, the air previouslydrawn into cylinder I and conned within that space constituting thedifference in volume between piston 2| and cylinder 1, Will becompressed and will be forced through outlet 38 into discharge pipe 40.

It can readily be seen that even though pistons 2| and 22 areeccentrically mounted upon shaft I3, the uniform angular displacement ofsaid eccentrics is such as to produce a dynamic balance. Consequently,shaft I3 may be driven at relatively high angular velocities withoutproducing an excessive amount of vibration. In addition, by theprovision of a plural number of cylinders, the pressure of the airdelivered is more or less` uniform throughout the cycle of operationdepending, of course, upon the number of cylinders used.

A pipe 4I may be threaded to boss lll and may communicate with conduit42 provided in said boss, said conduit also passing through bearing I2.An annular groove 43 may be provided in shaft I3 and a transverse bore44 may connect said groove to a longitudinal bore 45 provided in saidshaft. A transverse bore 46 may connect longitudinal bore 45 to thatportion of shaft I3 upon which eccentric I8 is mounted. Transverse bore41 may in like manner connect longitudinal bore 45 to that portion ofshaft I3 upon which eccentric I'I is mounted. Bore 48 in similar mannermay connect longitudinal bore 45 with that portion of shaft I3 carriedin bearing Pipe 4| at its opposite end may be connected to a source oflubricating oil or grease under pressure, not shown, and as can readilybe seen, said lubricant may be forced into longitudinal bore 45, fromwhence it may be delivered to bores 46, 41 and 48 which in turn permitthe passage of. the lubricant to the various moving parts of the pump.It can readily be seen that shaft I3 at one end is positively sealed byplug I4 whereas packing I6 prevents leakage of lubricant along theopposite portion of shaft I3.

By means of the dynamic balance secured by our invention and the more orless constant load carried by the prime mover, said pump may be directlyconnected to, for instance, a relatively high speed electric motor andwill perform with a maximum efciency. Heads 3 and 4 may be provided withintegral lugs 49 and 50 which extend beneath the lower portion of drumsI and 2, legs or standards 5| and 52 may be secured to lugs 49 and 50 bymeans of screws 53, whereby said pump may be mounted upon the same framethat supports the prime mover.

It can readily be seen that a pump constructed in accordance with theconcepts of our invention can be used to pump fluids of. substantiallyall types, the same being ideally adapted for pumping or compressingair, or other compressible gases or pumping incompressible liquids.

Referring particularly to Figs. 6 and 7, a slightly modified form ofport construction is shown, wherein I and 2' indicate the drumscomprising the casing of the pump. 'I'he upper portion of said drums maycarry a boss 3' which may be formed integral with said drums. Saidbosses may be provided with a plurality of bores 5', which may connectat their lower ends with counterbores 3' which, in turn, may be incommunica,- tion with the interior of said drums. A piston 'I'.identical in construction to pistons 2| and 22 may be positioned withineach of the drums I' and 2', said pistons being mounted and beingoperable within the drums in a manner identicall with pistons 2| and 22.

A transverse bore 8 may be provided in the upper portion of drums I and2', said bore being closed at one end and connecting with an exhaustoutlet (not shown) at the opposite end. Another bore 9 may be providedimmediately beneath and parallel to bore 8', said bores being incommunication with each other. A pair of semi-cylindrical members I0'and Il may be positioned in bore 9' above each of the drums I' and 2',each pair being independent and operating separately. A vane |2' may becarried in a slot I3' provided in each of the pistons 'I'. said vanesbeing secured in said slots by means of pins |4. The upper portions ofeach of said vanes |2 may extend into bore 9', each vane being slidablypositioned between each pair of semi-cylindrical members I0' and Theupper ends of vanes 9' extend into bore 8'. Each vane 9' may be providedwith a plurality of bores I5' which may be in communication at theirupper ends with bore 8. The lower ends of bores 5' may connect withopenings I6' which may serve to establish communication between boresI5' and the interior of each of the drums and 2'.

In operation, each of the pistons 'I' may travel in an orbital mannerwithin drums I and 2' similar to the travel of pistons 2| and 22. If thepistons I are driven in a counterclockwise direction,

as viewed in Fig. 6, uid win be drawn into the drums through bores 5'and 6 and will be compressed by said pistons and subsequently dischargedthrough openings I6 and bores I5 into bore B and from thence to thepoint of use.

Referring particularly to Figs. 8 and 9, another modied form of portconstruction is shown, wherein I" and 2" indicate the drums comprisingthe casing of the pump. The pump may, in general, be similar to thatshown in Figs. 1 and 3. Each of the drums l and 2" may be closed byheads 3, one only of which is shown, both of said heads being similar inconstruction. A boss 4" may be formed on each of said heads and may beprovided with opening 5" which may communicate with the interior of thedrums. A piston 6 may be positioned within each of the drums l" and 2",said pistons being mounted and being operated similar to pistons 2| and22. Each piston 6 may be provided with a bore 1" which may extendtransversely across said pistons, said bores being normally closed ateach end by heads 3 and a division wall 8 which separate drums I and 2".A plurality of bores 9" may connect the exterior of each piston and eachbore 1".

The arrangement is such that as pistons 5" travel in their orbitalpaths, at one period of travel, one end of each of the bores 1" comesinto communication with openings 5", thereby inducing fluid throughopenings 5 intol the respective drums. 'I'he discharge arrangement issimilar to that shown in Figs. 6 and 'l and is indicated as such bysingle-primed reference numerals.

It is to be understood that the features of the constructions shown maybe utilized in single chamber pumps having single pistons, in which casethe pump shaft may be dynamically balanced by means of a separatecounterweight.

We claim as our invention:

A pump for uids comprising in combination, a hollow casing having acylindrical interior, walls at the ends of said casing, one of saidwalls being provided with an opening, a piston eccentrically positionedin said casing and movable in a planetary manner therein, a hollow Vanemounted upon said piston, said vane being movably associated with saidcasing to prevent rotation of said piston, the hollo-w interior of thevane being in communication with the interior of the casing during aportion of the movement of the piston, said casing being provided withan outlet opening in communication with the hollow interior of the vane,said piston being provided with an aperture which during a portion ofthe movement of the piston is in direct registration with the opening inthe casing wall, said piston also being pro'- vided with a communicationbetween the apery ture provided therein and the interior of the casing.

WALTER H. HERMSDORF. ALLAN W. ARONER.

